1. The Field of the Invention
The present invention relates to apparatus for applying dental agents to tooth surfaces. More particularly, the present invention allows a dentist to quickly and precisely apply a proper quantity of dental agent to tooth surfaces which have been prepared to receive the dental agent. The present invention is ideally suited for applying dental bonding agents to tooth surfaces.
2. The Prior Art
Bonding agents play an important role in dental restorative techniques. Generally, bonding agents are applied to tooth surfaces in order to firmly attach a restoration to the tooth. When the restoration is a composite resin restoration, the composition of the bonding agent is usually that of the matrix of the composite resin.
Before applying a bonding agent, the enamel around a cavity preparation is etched with acid. Acid etching of enamel creates micro-irregularities on the enamel surface. The resin in the bonding agent is usually diluted with monomers so that it has a low viscosity which can readily penetrate into the microscopic irregularities and undercuts produced by the acid etching. The bonding agent is then polymerized. It is believed that when the composite restorative resin is inserted into the cavity, it will polymerize to the bonding agent present on the cavity surface. In this way, better adaptation to the enamel walls of the cavity is achieved with improved mechanical retention of the restoration.
Various devices have been used in the art for applying dental bonding agents to tooth surfaces. One device used to apply dental bonding agents is a small porous sponge or swabbing material. In practice, a quantity of bonding agent is applied to a transfer pad. A sponge is then grasped with forceps and dipped into the bonding agent. The wetted sponge is then rubbed across the tooth surface in order to apply the bonding agent.
The small sponges are disposable to prevent cross-contamination. However, the sponges do not permit accurate application of the bonding agent. Frequently, the bonding agent is applied to surrounding surfaces which do not need treatment. Moreover, the rubbing action required to apply the bonding agent necessarily damages the fragile crystalline surface structure of the tooth formed during acid etching. Once the crystalline surface structure of the tooth is damaged, its bondability is reduced.
Another existing device for applying bonding agent to tooth surfaces is a small disposable brush tip. Like the sponge, the brush tip must be held with forceps or some other holding device. The brush tip is then dipped into a quantity of bonding agent placed on a transfer pad.
Like the sponge, the brush tip is disposable. In addition, the brush tip does not damage the fragile crystalline structure of the tooth surface produced by acid etching. However, like the sponge, the brush tip must constantly be rewetted by the bonding agent during the dental procedure. Moreover, the disposable brush tips used in the art usually have long bristles which do not form a fine tip. As a result, the bonding agent is often inadvertently applied to surrounding tooth surfaces.
Yet another device for applying bonding agents to tooth surfaces is a very fine paint brush. Such a brush can apply the bonding agent to tooth surfaces with precision and detail.
Despite its advantages, a paint brush must also be repeatedly dipped into a quantity of bonding agent during the procedure. In addition, a paint brush is difficult to properly sterilize and is usually nondisposable, thereby making it difficult for the dentist to maintain an aseptic environment. With the ever-increasing threat of Acquired Immune Deficiency Syndrome ("AIDS") in society, use of a nondisposable applicator which is also difficult to sterilize has become unacceptable.
Further, in each of the known devices for applying bonding agents to tooth surfaces, a quantity of bonding agent is placed on a transfer pad so that the device can be rewetted during the surgical procedure. Such a technique is not only wasteful, but is exposes the bonding agent to light, air, and airborne contaminants.
Moreover, time is often of the essence in applying bonding agents to tooth surfaces. As a result, it is important for bonding agents to be applied quickly and accurately. Thus, the need to constantly rewet the bonding agent applicator during the procedure is not only inefficient, but may reduce the effectiveness of the resulting bond between the restoration and the tooth surface.